Folding blinds for windows and doors

ABSTRACT

This invention relates to a bellows folding blind for windows and doors, comprising a number of horizontal slats connected among to each other by means of adequate joints which, when the blind is raised enable the slats to automatically fold like an accordion inside the box. On each slat are applied three pins which are engaged by the teeth of the cams whose rotation allows the raising and lowering of the blind. The helicoidal screws synchronised with the cams engage the longer pin and allow the supporting, raising and lowering of the package of horizontal slats inside the box.

TECHNICAL FIELD

This patent application for industrial invention concerns a foldingblind for windows and doors.

BACKGROUND OF ART

As it is well known, blinds for windows and doors, one type beingcommonly known as rolling shutter and the other as roller blind havebeen till now rolling devices made up by a series of horizontal slats,connected to each other by means of appropriate joints that enable themto sway with respect to each other so that they can spiral around anhorizontal spindle whose rotation can be driven either manually by meansof belts or automatically by means of an electric motor. The upper slatis made integral with such spindle on which the whole weight of theblind is discharged, and in fact the spindle rests on heavy supports,permanently fixed to the wall.

One of the drawbacks of rolling shutters and roller blinds isrepresented by the complexity of installation, that requires a doublework of masonry: the first to fix the supports of the spindle, and thesecond to fix the wooden box, with which is plugged the spindle well.

Another drawback of rolling shutters is due to their crosswise volumewhen completely rolled, namely when they are completely wrapped aroundtheir spindle. Such volume is almost always greater than the depth ofthe well into which the blind is to be housed, and therefore such boxinevitably props up with respect to the inner face of the wall, thusdetermining two types of drawbacks: the first of a purely aestheticnature and the second of a technical nature, consisting in the fact thatthe curtains have to be put at a certain distance from the wall, whichincreases according to the jut of the box, since the curtains areusually mounted on a surface facing the box, so that the latter can becovered and hidden by the curtains themselves.

All this practically determines a loss in the useful surface of the roomwith respect to the cases in which the curtains can be positioned closeto the wall.

The aim of this invention is to conceive a blind for windows and doorsthat, at its maximum compaction, i.e. when the blind is completelyraised, may have a crosswise volume remarkably lower than that ofexisting folding blinds and in any case such as not to overcome thedepth of the box well in which they are contained, so that their housingand covering box can stay perfectly flush with respect to the inner faceof the wall.

Another aim of this invention is to conceive a blind for windows anddoors whose components can be installed and supported within its housingand covering box, so that the installation can be easier and faster,consisting in simply inserting and anchoring the box into theappropriate well.

Over the years, a certain number of devices were conceived to find asolution to the above described drawbacks: the patent DE A 29 47501describes for instance a folding blind for windows and doors whose slatsare articulated among them by means of a curved-end joint, and equippedwith pins at the ends of the slats; the pins run within two lateralslideways (17,18) and a gearwheel, driven by a motor or a belt, engagesthe pins and pushes open or closed the slats; when they are opened, theslats should arrange like an accordion. In the above patent theslideways run from the base of the blind to the lower face of thegearwheel, and therefore the slats have no runner above the gearwheel.This entices a not ordered arrangement of the slats that impairs theoperation of the blind. As suggested by the drawings annexed to thedocumentation, the above said blind could at best be suitable for rooflights, where the almost vertical arrangement of the blind may help theslats arrange as desired. In case of vertical placement of the blind,the probability that the slats arrange themselves in the right way isalmost nil; in fact, in a variant described and illustrated in thepatent, the slats are wrapped around a pin, thus thwarting theadvantages of a folding accordion-like blind. The U.S. Pat. No. 4,303,117 describes an opening and closing device for accordion-likeblinds in which the slats, equipped with lateral pins, run within twoslideways and are provided with weights that, making them heavier,enable them to be lowered; the slats are raised applying the power totwo ropes connected to the lowest slat: the slats are bent by means oftwo ropes and two cams which are also required to overcome the peak loadexisting in the joints, since the raising cables hold the slatarrangement tightened both when raised and when lowered; in order tofacilitate the movement of the blind, a system of counterweights isrequired. The system described in the U.S. Pat. No. 4,303,117 is rathercomplex, costly and, when moving the blind, it causes several frictionsdue to the sliding of ropes, to devices 25 and 26 which induce bendingof panels, to the friction deriving from counterweights; moreover thesystem described in such patent remarkably increases the weight to beraised and its motion is not perfectly uniform, due to thecounterweights.

Also the Italian Patent no. 01286983-PCT/IT/00120 conceived anaccordion-like folding blind that during realisation created problemswhen operating, since the package of slats above the cam was notadequately guided and supported.

DISCLOSURE OF INVENTION

This invention consists in a blind for windows and doors which, besidesbeing capable of being installed within boxes of small dimensions owingto the accordion-like bending of slats, may also remove the abovementioned drawbacks by means of a safe bending of slats thanks to asimple mechanism providing minimum weight and friction, with adequatesideways and safe support of the package of slats above the cam.

These objectives have been reached thanks to the subject blind whichincludes a series of horizontal slats connected to each other by meansof adequate joints which enable, when the the blind is raised, anautomatic bellows closing of the slats as they enter the box. Thecrosswise volume of such blind, inside, practically corresponds to thewidth of a slat, since all the slats rest exactly one above the other,thus forming a stack of constant width, independently from the number ofslats forming the blind, contrary to what happens with rolling blinds,whose spiral has a diameter which increases with the number of slatsthat compose the blind.

The upper slat is free and when completely raised, it is in contact withthe upper part of the box, while when completely lowered it rests abovethe cam, in order to reduce the overall height of the slat panel.

Raising and lowering are obtained through the rotation of two centriccircular toothed cams that engage the pins of the slats, thusdetermining upwards and downwards drive. The two lateral cams are driveneither manually through a belt or automatically through a series ofgearwheels connected by means of a transmission spindle; gearwheels arehoused within a metal box, having the required dimensions, and suitableto support the strength for raising and lowering the slat panel, and allthis is housed inside the wall box. Since the spindle has not to supportthe weight of the blind, the relative supports may safely be fixed tothe walls of the box, that in this way will contain the blind and allits operating mechanisms.

This means that the installation of such blind may be done in only onephase, during which the box, and the blind inside it, are inserted andembedded in the appropriate opening of the wall.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to clarify explanation, this description continues withreference to the annexed drawings, which have only an illustrative andnot a restrictive value, and where:

FIG. 1 shows in a perspective and schematic representation the blindcompressed within its box;

FIG. 2, 3 and 4 show respectively a couple of slats when in coplanar anddetached position, coplanar and close position, overlapping position,one settled on the other.

FIG. 5 is a schematic view of the left end of the box;

FIG. 6 is a view of FIG. 5 folded accordion-like;

FIG. 7 is a schematic view of the left end of the box having a simplersupport system fort the panel of slats;

FIG. 8 is a view of FIG. 7 from left to right, containing the two upperslats during the bending phase.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the above figures, the blind is made up by a series ofconnected slats (1) linked together by means a flat section (2) withlongitudinal hook-like bent sides (2 a), engaged by means of appropriateloops along the longitudinal sides of each slat. In particular, on theupper side of each slat (1) there is a longitudinal loop (1 a) having asemicircular profile developing around a round longitudinal rib (1 b)with which the lower side of the section (2) is engaged, while on thelower side of each slat (1) there is a deep longitudinal loop (1 c)almost rectangular in its shape, on whose mouth is envisaged a roundlongitudinal rib (1B) corresponding to the one above (1 b) and to whichis engaged the hook-like side of the section (2).

The depth of the loop (1 c) is such that the latter may house a part ofsection (2) when two slats (1) arranged on their edge in coplanarposition arrive directly in contact between them, as indicated in FIG.3.

It should be pointed out that the loops (1 a and 1 c) are not in thesame position with respect to the centre and are placed in opposedposition on each slat (1) and therefore the slats (1) have to beconnected in alternate position so that the upper loop (1 c) of one maybe interfaced with the lower loop (1 a) of the immediately overhangingslat (1). Over each end of the slats (1) three pins are applied (3 a, 3b and 3 c) which are used to engage the slat (1) by the cam (9) forraising and lowering; outside the box, the slats (1) are superimposed toeach other edgewise.

Inside the box (6) the slats (1) are closed accordion-like, lying oneach other, forced in such position by the hoist of cams (9) and by theslideways (8 a, 8 b and 8 c) and by the pin (3 a) which is longer thanpins (3 b and 3 c), housed into the respective metal box (8). Withreference to FIG. 6, the upright slideways (7) in which the slats (1)run, have an appropriate seat (7 a) for housing and sliding of pins (3a, 3 b and 3 c).

Inside the box (6) besides the cams (9) the transmission spindle (5) andappropriate slideways are envisaged (8 a, 8 b and 8 c), anchored to theinner face of the two boxes (8). To be more precise, on both the leftand right sides of the box (6) and close to the slats (1) and to thecams (9), a slideway (8 a) is realised, whose lower part isintercommunicating with the seats (7 a) of the upright slideways (7),since the above slideway is intended to receive the pins (3 a) as theslats (1) are gathered within the box (6).

On the inner part of each box (8), as it has been said, a slideway isrealised, which at a certain height, compatible with the folding ofslats (1) is divided into two wings (8 b and 8 c) to enable the passageof pins (3 a) while the package of slats (1), the cams (9) and the pins(3 b and 3 c) remain outside.

Into the air space of each box (8) are located and protected thegearwheels (10 and 11) that may act as a reduction gear.

The slideway (8 a and its wings 8 b and 8 c), less deep than theslideway (7 and 7 a), realised on the inner part of the box (8), musthave dimensions that enable the slats (1) to be folded in pairs andunfolded in pairs owing to the pin (3 a).

On the outer part of one of the boxes, namely on the face opposite tothe slideway (8 a) is anchored the spindle (5) which activates theblind.

In order to enable the support of the horizontal package of slats (1)which is formed in the point where the two arms of the slideways (8 band 8 c) become parallel and vertical, to prevent their uncontrolledfall and uniform raising and lowering, two helicoidal screws (13 a and13 b) are vertically mounted within the box, synchronised with themovement of the cam (9), having the function to support, raise and lowerthe horizontally positioned slats (1), by hooking the respective pins (3a). The synchronism is transmitted to the helicoidal screw (13 b) by thescrew (13 a) by means of a toothed belt (12).

As it has been said, the package of slats (1) according to the directionof rotation of the two helicoidal screws (13 a and 13 b) which hook thepins (3 a) of respective slats (1) is lfted or lowered, since each slatis hooked by means of its pin (3 a) its weight is discharged on thetooth of the helicoidal screw (13 a or 13 b), and this enables an evendistribution of the weight of the package, slat by slat. As analternative to the synchronised system cam (9)—helicoidal screws (13 aand 13 b) for supprt, raiseing and lowering of the package of slats (1),a simpler system was devised, as described in FIG. 7 and 8, using thesame slats (1), the same pins (3 a 3 b and 3 c), the same cam (9) havingrecourse to the synchronism cam (9)—cams (15 a and 15 b) which hook thepins (3 a) of the respective slats. The synchronism is realised throughcircular toothed wheels placed inside the casing (14). Other systems forsupporting, raising and lowering the package of slats (1) can berealised with drive chain systems.

What is claimed is:
 1. Folding blinds for windows and doors comprising:a box, said box having two ends, a transmission spindle connected toeach of said two ends of said box, two cams, wherein one of said twocams is present in each of said two ends of said box, one or moregearwheels in operation with each of said two cams, a series of slats,each of said series of slats comprising a first side and a second side,said first side having an upper longitudinal loop therein and saidsecond side having a lower longitudinal loop therein, and three pins oneach of a first end and a second end, respective wherein said three pinson said first end and said second end serve respectively as hooks forsaid one of said two cams present on each of said two ends of said box,a plurality of flat sections wherein each flat section has a firsthook-like side and a second hook-like side, wherein said first hook-likeside of said each flat section hooks said upper longitudinal loop ofsaid first side of one of said series of slats, and said secondhook-like side hooks said lower longitudinal loop of said second side ofan adjacent slat, a slideway operatively positioned to each of said twocams, each said slideway bifurcating into a first arm and a second arm,said slideway housing a first pin of said three pins of said each slat,wherein said first arm is adapted to receive said first pin of a firstslat of said series of slats and said second arm is adapted to receivesaid first pin of a slat succeeding said first slat of said series ofslats, such that successive first pins of said series of slats alternatebetween being received in said first arm and received in said second armof said slideway, and two helicoidal screws wherein each of said twohelicoidal screws is vertically mounted in each of said two ends of saidbox with one end of said two screws being at a level where said firstarm and said second arm of said slideway take a parallel and verticalshape to said two helicoidal screws, said two helicoidal screws beingsynchronized respectively with movement of said one of said two camspresent in each of said two ends of said box in order to support, raiseor lower horizontally positioned slats of said series of slats byhooking first pins of said slats.
 2. Folding blinds for windows anddoors according to claim 1, wherein said upper longitudinal loop has asubstantially semicircular profile with a longitudinal rib, and saidlower longitudinal loop has a substantially rectangular profile with alongitudinal rib, wherein said longitudinal rib of said lowerlongitudinal loop and said longitudinal rib of said upper longitudinalloop hold said first hook-like side and said second hook-like side ofsaid flat sections respectively, and wherein each said lowerlongitudinal loop has a depth that can house a part of one of said flatsections when said series of slats are arranged in a coplanar position.3. Folding blinds for windows and doors comprising: a box, said boxhaving two ends, a transmission spindle connected to each of said twoends of said box, two cams, wherein one of said two cams is present ineach of said two ends of said box, one or more gearwheels in operationwith each of said two cams, a series of slats, each of said series ofslats comprising a first side and a second side, said first side havingan upper longitudinal loop therein and said second side having a lowerlongitudinal loop therein, and three pins on each of a first end and asecond end, respect wherein said three pins on said first end and saidsecond end serve respectively as hooks for said one of said two camspresent on each of said two ends of said box, a plurality of flatsections wherein each flat section has a first hook-like side and asecond hook-like side, wherein said first hook-like side of said eachflat section hooks said upper longitudinal loop of said first side ofone of said series of slats, and said second hook-side of an adjacentslat, a slideway operatively positioned to each of said two cams, eachsaid slideway bifurcating into a first arm and a second arm, saidslideway housing a first pin of said three pins of said each slat,wherein said first arm is adapted to receive said first pin of a firstslat of said series of slats and said second arm is adapted to receivesaid first pin of a slat succeeding said first slat of said series ofslats, such that successive first pins of said series of slats alternatebetween being received in said first arm and received in said second armof said slideway, and two circular toothed cams mounted in said box at alevel approximate where said first arm and said second arm of saidslideway take a parallel and vertical shape, said two circular toothedcams being synchronized respectively with movement of said one campresent in each of said two ends of said box in order to support, raiseor lower said series of slats by hooking respective first pins of slatsof said series of slats.
 4. Folding blinds for windows and doorsaccording to claim 3, wherein said upper longitudinal loop has asubstantially semicircular profile with a longitudinal rib, and saidlower longitudinal loop has a substantially rectangular profile with alongitudinal rib, wherein said longitudinal rib of said lowerlongitudinal loop and said longitudinal rib of said upper longitudinalloop hold said first hook-like side and said second hook-like side ofsaid flat sections respectively, and wherein each said lowerlongitudinal loop has a depth that can house a part of one of said flatsections when said series of slats are arranged in a coplanar position.